This invention relates generally to bill validators for vending machines or the like and particularly to a bill validator having an improved transport system for conveying the bills to a bill collection compartment.
In general, bill validator transport systems of the type under consideration, which convey bills from a receiving slot to a location adjacent a collection compartment by gripping the edges of the bill, so that it can then be pushed into a collection compartment, are of two types. In the first type of transport system, represented by U.S. Pat. No. 4,887,808, the bill edges are sandwiched between spaced pairs of engageable belts, one pair of spaced belts being idler belts. This system suffers from the disadvantage that the gripping ability of the paired belts which engage the edges of the bill must be carefully controlled since insufficient pressure results in bill slippage while too much pressure results in the problem of pushing the bill into the collection compartment. In the second type of transport system, represented by U.S. Pat. No. 4,678,072, the bill edges are sandwiched between spaced pairs of belts and spaced sets of spring-biased rollers. While this system offers some tension control between the gripped edges of the bill it lacks the continuity of gripping which is available along the full length of the bill where double belts are used and, in addition, the spring-biased rollers require careful mounting and adjusting to ensure correct bias and add additional mechanical parts.
The present bill transport system is an improvement of the first type of transport system and overcomes the problems discussed above in a manner not disclosed in the known prior art.